Spoilers are typically provided on the upper aerodynamic surface of an aircraft wing, between the main fixed wing box and the trailing edge flaps. The performance of the flaps can be improved by attaching them to the fixed wing box by drop hinge mechanisms. This allows the flaps to be deployed in both aft and downward directions and to be rotated downwardly (or “drooped”). When the flaps are fully deployed in this way, gaps are formed between the trailing edges of the spoilers and the leading edges of the flaps. Small air gaps in these regions improve lift when compared to conventional Fowler flaps. However, if these gaps are too large and the continuity of the upper aerodynamic surface is not maintained, then the performance of the flaps is reduced. To control the size of these gaps, the spoilers are rotated downwardly (or “drooped”) when the flaps are fully deployed.
The spoilers are typically attached to the fixed wing box by structural ribs. However, it is necessary to prevent the leading edges of the spoilers from clashing with the structural ribs when the spoilers are deployed to their braking position. One way in which this can be done is to provide notches in the structural ribs to accommodate the deployed spoilers. However, in this configuration, the necks of the ribs are subject to increased stress concentrations which require them to be thickened. Moreover, the shroud panels which are bolted to the upper arms of the ribs must also be thickened to prevent them from fluttering in the air flow. There is therefore a weight penalty associated with this solution. The load paths are also more complex.
An alternative method of preventing clashing between the spoilers and the ribs is to provide cut-out sections in the leading edges of the spoilers. However, when the spoilers are in their cruise positions, the cut-out sections act as discontinuities in the path of the air flow, increasing drag and noise. Consequently, for the optimum performance of this type of arrangement, the cut-out sections need to be sealed, while allowing the spoilers to rotate over their entire pivotal range without clashing with the structural ribs.